This invention relates to a speed sensing device for a wheeled vehicle and more particularly to a speed sensor particularly adapted for use in a skid control system.
In many instances it is desirable to provide a signal indicative of the rotational speed of a wheel on a vehicle. Such speed sensing devices are commonly used to provide an input signal to the computer of a skid control system for processing to determine variations in wheel speed or wheel acceleration and decelaration rates. Such devices should permit convenient mounting and should also be low in cost. Somewhat inconsistent with these requirements is the requirement that the device provide an accurate indication of wheel speed regardless of axial, angular or radial variations in the location of the rotating element, which variations arise from manufacturing tolerances. Furthermore, it is essential that the speed sensing device not be subjected to extreme loadings as a result of such variations.
It is, therefore, a principal object of the invention to provide an improved speed sensing device that accommodates variations in spacing between the rotating and fixed elements of the associated vehicle.
It is another object of the invention to provide a speed sensing device that may be positioned in a cavity at the outer end of a vehicle axle.
It is a further object of the invention to provide an improved construction for an in-axle wheel speed sensor and an improved driving arrangement therefor.